1. Field of the Invention
The present invention relates generally to apparatus and methods for wrapping articles, and relates more particularly to such apparatus and methods useful for wrapping articles such as candy bars or other food products in a manner incorporating a wrap such as a single or double twist-wrap, an envelope wrap, a bunch wrap or a modified envelope wrap. The invention is applicable to wrapping performed with either a heat sealing method or a cold-seal adhesive.
2. Related Background Art
The great majority of candy bars are packaged by being wrapped and sealed in a film of wrapping material, on which is printed the desired package artwork, logos, etc. Such wraps are generally formed in the following way. A continuous film of the wrapping material is printed with the artwork and the like (this is generally done by the vendor of the film, not by the food packager). In the actual packaging process, the products are deposited in the film with proper registration, so that the individual products line up with the artwork on the film. The film is wrapped around the products 12 and sealed in a continuous seam 14 to form a tubular shape 16 (see FIG. 2). This tube 16 is then cut into parts at the correct locations to produce individual tubular lengths of film, each containing one product. Both ends of each of these are then sealed by heat sealing methods or cold-seal adhesive, completing the formation of the familiar wrapped product 20 (see FIG. 1). Commonly, the cutting and the sealing are performed simultaneously, by a mechanism known as a cut-and-seal. These techniques are referred to herein as the conventional xe2x80x9cflow-wrapxe2x80x9d process.
Another form of wrap for food products, such as candies, involves wrapping individual pieces of the product in a film that is wrapped around the product, again in a tubular fashion, with a twist in each end (see 30, in FIG. 3). Small hard candies wrapped in this manner are also a familiar product. (In contrast to this double twist-wrap, various other twist-wrap techniques are used for other products, such as lollipops. Other types of wrapping techniques useful for various food products are the envelope wrap, the bunch wrap and the modified envelope wrap. These wrapping techniques are well understood by those of ordinary skill in the art, and together with the double twist-wrap will be termed xe2x80x9cspecial wrapsxe2x80x9d or xe2x80x9cspecial wrapping techniquesxe2x80x9d herein.)
It would be desirable to provide an apparatus and a method capable of wrapping products, such as candy bars, with a double twist-wrap. It would be especially desirable to provide a modular apparatus that could be used with a standard continuous flow-wrap line of the type used for wrapping candy bars, so that the continuous flow-wrap line could be used as desired either to turn out double twist-wrapped product 30, or product wrapped in the familiar packaging 20 with both ends of the wrap sealed in a flat shape.
In addition, it would be desirable to provide a modular apparatus that could be used with a standard continuous flow-wrap line of the type used for wrapping candy bars with one or another of the special wrapping techniques mentioned above, including bunch wrap, single twist wrap, envelope wrap, and modified envelope wrap, such that the continuous flow-wrap line could be used as desired either to turn out product wrapped using such special wrap, or product wrapped in the familiar packaging with both ends of the wrap sealed in a flat shape.
Accordingly, it is one object of the invention to provide an apparatus that enables one to form such a double twist-wrap packaging for articles reliably and at a high speed.
It is another object of the invention to provide such an apparatus that can be attached to a flow-wrap line for twist-wrapping (or other special wrapping), and can be deactivated when the line is to be used for standard continuous-flow wrapping.
It is still another object of the invention to provide a double twist-wrap apparatus having a twist-wrap mechanism that effects the twist-wrap reliably, and which is actuated only when necessary for that purpose, and which is deactivated between the end of formation of one twist-wrap and the beginning of the formation of another twist-wrap by the mechanism.
According to the present invention, these objects are achieved by providing a modular special-wrap apparatus that has a receiving portion, arranged to receive a partially-wrapped article, for example a tube-wrapped article, into a predetermined location, from another machine, and a special-wrap assembly that forms the desired special wrap. For a double twist-wrap, the special-wrap assembly has rotatable twist grippers to grip the ends of the partially-wrapped article, and to twist the ends to form a twist-wrapped article.
According to another aspect of the present invention, these objects are achieved by providing a flow-wrap packaging line for wrapping a series of individual articles, which has a first section, in which a film is formed into a tubular wrap about the articles, a cut-and-seal section, in which the tubular wrap is cut between each two successive articles, and a twist-wrap or other special-wrap section, which may be detachable but in any event is capable of being deactivated to permit use of the flow-wrap packaging line without the special wrap. The cut-and-seal section is operable in a first mode, in which the tubular wrap is also sealed, thereby completing wrapping of the articles, and in a second mode, in which the tubular wrap is cut but not sealed. The special-wrap section has a receiving portion, arranged to receive a tube-wrapped article into a predetermined location, from another machine (i.e., the cut-and-seal section), and a portion that forms the desired special wrap. In the case of a twist-wrap, the special-wrap section has rotatable grippers to grip ends of the tube-wrapped article, and to twist the ends to form a twist-wrapped article.
According to another aspect of the invention, these objects are attained by providing a twist wrap apparatus that has a receiving portion, arranged to receive a tube-wrapped article into a predetermined location, from another machine, and a twist-wrap assembly. The twist-wrap assembly has rotatable twist grippers to grip ends of the tube-wrapped article and to twist the ends to form a twist-wrapped article, and includes a twist-wrap drum and Geneva wheels that drive the twist grippers.
Other features and advantages of the present invention will be more fully understood from a consideration of the following detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings.